I’ve decided to change my ground radials on the 30 meter vertical. I’m limited in how many radials I can lay out with the current box setup and through checking via the MFJ I am still getting 40 ohms at reactance (even with all this wet weather), and really I'm looking for the standard 36 ohms and I'm certain it's down to the number of radials I currently have laid out. So I am going to make a simple ground radial plate with a minimum of 60 connections hopefully more if I can fit them in.
What’s fascinating is the different types of plates you can find on the market and the prices. Basically all I’m looking for is a good piece of plate aluminium which I can cut to size, add a connector for the coax and drill as many holes as I can around the edge. Looking on Ebay last night I managed to pick up a fairly chunky plate for £2.00 which I’m now waiting to arrive. Some plates I’ve seen on the internet can cost as much as £40.... crazy!
Here’s a few examples that I particularly like and may have ago at copying.
This home brew plate looks fairly simple with the antenna connector coming up through the middle but it looks as if its limited with connector numbers, to get round this and similar to my box there is more than one wire connected to each bolt.
Here's the DX Engineering favourite which I might well use to copy but put the coax connector plate on the edge instead of the middle. It's a nice big chunky plate that will probably last for years.
Home brew "Tiny plate", looks like an old sink drain! But hell as long as it works.
This is from a UK company called Antenna Engineering, I like the way the coax connector is bolted on to the plate and a good strong simple ground spike too. The company does some great antennas and is well worth a look.
And here's my present box, it works fine but you can see I'm limited on the amount of radials I can insert (20 but I can double up) and although it's an ideal light weight box for portable work it really could be much better now I've got it permanently set up in the garden.